Due to the introduction of ultrasound, the acquisition of new anatomy and sonoanatomy knowledge, as well as recent discoveries on the role of the fascia, regional anesthesia has undergone a process of "evolution-revolution" in the last decade and now is playing a key-role in surgery and postoperative pain management, allowing opioid-sparing or opioid-free strategies, in line with the ERAS pathway. With the contribution of the most prominent experts in the field, this book is a milestone for all professional figures involved in anesthesiology and pain therapy, thanks to the drawings, tables, flow charts, detailed anatomical and sono-anatomy pictures and clinical cases included in each chapter. The volume includes a chapter dedicated to the anatomy and function of fascia, a section on paraneuraxial block describing the paravertebral block and the ESP block in the countless fields of application, a section dedicated to the anterior thoracic blocks, a section on blocks of the anterior and posterior abdominal wall, a chapter on pediatric wall blocks, several chapters ranging from the neck band blocks, to the application and indication of the LIA and Wound infusion and an innovative chapter on the application of RA techniques in the COVID era.